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In a decision rendered by Singapore’s Court of Appeal on 1 August 2017, the Court of Appeal dismissed an appeal to make various amendments to patent claims, reasoning that the granted claims were obviously invalid to begin with and that there was undue delay by the plaintiff in seeking amendments.

(A) Who are the parties involved in this case?

Warner-Lambert Company LLC (Plaintiff)

Novartis (Singapore) Pte Ltd (Defendant)

(B) What actually happened?

The Plaintiff was the registered proprietor of a pharmaceutical patent which claims monopoly over use of a substance known as pregabalin for the treatment of pain (the “Patent”).

The Patent was filed on 16 July 1997 and granted in Singapore on 23 May 2000. Its 20-year protection expired on 16 July 2017.

On 23 March 2015, the Plaintiff received notification of the Defendant’s applications to the Health Sciences Authority (“HSA”) for product licences for pregabalin products, pursuant to a requirement under the Medicines Act (Cap 176).

In the notification, the Defendant claimed that the Patent would not be infringed by the acts for which the product licences were sought.

On 21 April 2015, the Plaintiff commenced a suit against the Defendant, seeking a declaration that the Patent would be infringed by the Defendant if the Defendant did the acts for which the product licences were sought.

On 5 May 2015, the Plaintiff informed the Defendant of its intention to amend the Patent.

On 2 June 2015, the Defendant filed its defence and counterclaim seeking revocation of the Patent on the ground that the Patent was invalid as it claimed a monopoly over methods of treatment of the human or animal body, something impermissible under Singapore’s patent law. Section 16(2) of the Patents Act provides that such methods of treatment shall not be taken to be capable of industrial application. One of the requirements of a patent is that it must be capable of industrial application.

On 26 August 2015, the Plaintiff applied for leave to amend the Patent pursuant to Section 83(1) of the Patents Act, aiming to cure the invalidity in the Patent’s granted claims (“Granted Claims”).

(C) Procedural History

The High Court judge (the “Judge”) dismissed the Plaintiff’s application to amend the Patent, as the Judge was of the view that the amendments would extend the scope of protection of the Patent.

The Judge further held that there had been undue delay by the Plaintiff in seeking amendments which warranted the exercise of the court’s discretion to disallow the amendments.

Plaintiff appealed against the Judge’s decision.

(D) What is/are the present issue(s) in dispute?

Issue 1: Whether the proposed amendments to the Patent would extend the scope of protection conferred by the Patent, in contravention of Section 84(3)(b) of the Patents Act.

Issue 2: Whether the Court of Appeal should exercise its discretion to refuse the amendments on the ground that the Plaintiff had delayed for an unreasonable period before seeking to make the amendments.

(E) Holding

Issue 1:

The Court of Appeal held that when a patent granted under the self-assessment system (i.e. old regime which currently only applies to patent applications with filing dates up till 13 February 2014) is obviously invalid in its totality and such invalidity is attributed solely to the patentee, there is no need to even consider whether the proposed amendments extend the protection conferred by that patent. The onus is on the patentee to ensure compliance with the requirements in the Patents Act under the self-assessment regime. As the granted claims, being method of treatment claims, were obviously invalid, the Court of Appeal held that it would disallow the amendments sought by the Plaintiff on this ground.

In any case, the Court of Appeal also considered that the amended claims indeed extended the scope of protection covered by the granted claims. The crux of the inquiry is whether the ambit of the protection conferred by the patent will be extended by the proposed amendments. In essence, this would be an exercise of interpreting the claims purposively and examining the scope of the invention for which the patent was granted. The Court of Appeal held that the Plaintiff, by seeking to amend method of treatment claims to Swiss-style claims (Swiss-style claims are claims to a process of manufacture of a medicament for the purpose of the new therapeutic use of the known compound), would extend the scope of protection covered by the granted claims. This is because the amended claims involve a link between the act of manufacture and the ultimate intended use of the drug by the end-user to treat pain, rather than merely the new therapeutic use of the drug itself (which was the essential feature of the original granted claims).

Issue 2:

As for the issue of undue delay, the question is whether the patentee delayed in seeking the amendments and, if so, whether there was a reasonable explanation for such delay.

A patentee’s actual or constructive knowledge of the need to amend should, in appropriate circumstances, suffice to disentitle the patentee to the favourable exercise of the court’s discretion.

The appropriate juncture to question whether the amending party has been guilty of an unreasonable delay is the time it was first made aware of the need to amend.

The Court of Appeal decided that the amended claims should be rejected on the basis of the undue delay by the Plaintiff in bringing the amendment application. The delay by the Plaintiff in this case was for more than a decade after having actual/constructive knowledge of the need to amend, and it had no reasonable ground to excuse the long delay.

The Plaintiff’s appeal was accordingly dismissed.

(F) Rationale for holding

Issue 1:

The Court of Appeal held that when a patent granted under the self-assessment system is obviously invalid in its totality and such invalidity is attributed solely to the patentee, there is no need to even consider whether the proposed amendments extend the protection conferred by that patent.

The Court of Appeal held that the granted claims were obviously invalid since they were method of treatment claims violating Section 16(2) of the Patents Act. This meant that the Patent fails to meet even the threshold criteria for patentability. Such invalidity would be fatal to any amendment application. This is because the granted patent confers no protection whatsoever and the amendment application is seeking to validate that which was not valid from the beginning.

The Court of Appeal considered this strict approach justified because the patentee who obtains an obviously invalid patent under the self-assessment system obtains an effective monopoly over the subject matter. The onus is thus on the patentee to ensure compliance with the requirements in the Patents Act.

The above reasoning sufficiently disentitles the Plaintiff from amending the Patent. However, for the sake of completeness, the Court of Appeal went on to consider whether the amended claims extended the scope of protection of the granted claims, i.e. whether the amendments from method of treatment claims to Swiss-style claims extended the protection conferred by the Patent.

The Court of Appeal considered that the manufacture of the medicament for the purpose of treating pain, as stated in the amended claims, was not an act that fell within the ambit of protection of the granted claims. The amended claims protected the manufacture while the granted claims protected the method of treatment. As manufacture was not within the original scope of protection, there would clearly be an extension of the scope of protection.

Accordingly, the Court of Appeal disallowed the Plaintiff’s amendments.

Issue 2:

The Court of Appeal agreed with the Judge’s holding that there was undue delay on the part of the Plaintiff in seeking the amendments. The delay was for more than a decade and there was no reasonable ground to excuse the long delay.

It reasoned that a patentee should not be entitled to stand idle after discovering the need for amendment. At the end of the day, a patentee must act expeditiously in taking out an application to amend its patent claims upon discovering the risk of invalidity.

Any delay in taking out an application to amend must be capable of explanation, and the patentee cannot persist in refusing to amend its patent specifications in an unamended and suspect form despite becoming aware of the risk of invalidity.

An applicant’s actual or constructive knowledge of the need to amend should, in appropriate circumstances, suffice to disentitle the applicant to the favourable exercise of the court’s discretion. A patentee who has been exposed to facts from which it was, or reasonably ought to have been, apparent to him or her that a claim might well be invalid unless amended, but nevertheless brings a late application to amend, is in no position to say that there was, on the earlier occasion, no “need” to amend simply because it had not then been conclusively established that the claim was in fact invalid.

Ensuring the timeliness of patent amendments upholds the public interest in “preventing unworthy inventions and products form monopolizing the market”. Such an approach would also “take into account the public interest which is injured when invalid claims are persisted in so that inventors are legitimately warned off the area of the art ostensibly monopolized by the claims.

Under the self-assessment system then, the Plaintiff was under an obligation to make a considered decision before proceeding to obtain a grant of the Patent. The Court of Appeal opined that a self-assessment system should not give patentees the liberty of taking a lackadaisical approach in ensuring that their patent claims in the register comply with the requirements of patentability under the Patents Act. This is especially so as the grant of the Patent allowed the Plaintiff to enjoy a monopoly in the supply and sale of pregabalin in Singapore despite the clear invalidity of the granted claims. Adopting a lenient approach would only encourage dilatory conduct and willful blindness on the part of patentees, and cause invalid patents to remain on the register for longer than necessary.

Applying the above principles to the present case, the Court of Appeal held that the evidence showed that the Plaintiff knew or ought to have known that the Patent was problematic but chose not to take any steps to find out more or to amend the Patent:

In February 1998, the International Preliminary Examination Report (“IPER”) received by the Plaintiff put the Plaintiff on notice that method of treatment claims may be found inadmissible in some patent systems.

On 14 December 1998, the Plaintiff filed the Patent’s corresponding European application with an accompanying amendment to the claims from method of treatment claims to Swiss-style claims. This showed the Plaintiff had begun to take steps in other jurisdictions to remedy the potential invalidity arising in some patent systems but failed to do the same for the Patent in Singapore.

At various times in 2005, 2007 and 2008, the Plaintiff applied to amend its other Singapore patent applications pre-grant from method of treatment claims to Swiss-style claims but did not do the same for the Patent in question. This indicated that the Plaintiff was aware of the method of treatment exclusion as it was prompted to take action to make pre-grant amendments to other patents, but did not do the same for the Patent.

Given that the Plaintiff had actual and/or constructive knowledge that method of treatment claims were precluded from patentability in Singapore and that the Patent was wholly invalid as it contained exclusively method of treatment claims, the Court of Appeal opined that it was incumbent on the Plaintiff to apply to amend the Patent at the earliest possible opportunity, or seek legal advice in relation to the issue. It’s failure to act on this knowledge expeditiously amounted to unreasonable delay.

The Plaintiff also failed to provide proper explanation save for bare assertion that it did not receive any legal advice alerting it to the need to amend. This assertion was rejected by the Court of Appeal as no evidence was adduced in support of it. Also, given that the Plaintiff is an established pharmaceutical company with a sizeable patent portfolio, the Court of Appeal found that it was more likely than not that the Plaintiff was aware of the method of treatment exclusion and that it recognized the need to amend the granted claims.

Even though the Patent was sought and granted at a time when a self-assessment system was in place in Singapore, it was incumbent on the Plaintiff to be responsible for the validity of the Patent in the register. Monopoly rights that the Plaintiff enjoyed from the grant dictated that it should not stand idle and wait for challenges to validity or for infringement before it reviewed the validity of the Patent.

If it were to be taken that a patentee is put on notice only when it receives clear advice that its patent is problematic, patentees would be free to delay amending their patents by simply not taking advice.

For the reasons above, the Court of Appeal held that the Judge was right to disallow the proposed amendments on the basis that there was unreasonable delay on the part of the Plaintiff in taking out the amendment application.

G) Dicta
The Court of Appeal made some observations on novel issues that arose in the present case, namely:

Whether a second medical use for a known substance is patentable

Validity of Swiss-style claims in Singapore

The Court of Appeal made 2 tentative observations on the above issues:

The Patents Act appears to support the patentability of second and subsequent medical uses of known substances.

The Court of Appeal preferred a wider and purposive interpretation of Section 14(7) of the Patents Act which provides that “In the case of an invention consisting of a substance or composition for use in a method of treatment of the human or animal body by surgery or therapy or of diagnosis practiced on the human or animal body, the fact that the substance or composition forms part of the state of the art shall not prevent the invention from being taken to be new if the use of the substance or composition in any such method does not form part of the state of the art”.

It opined that Section 14(7) does protect any use, first or subsequent, which is not part of the state of the art. Hence, the substance or composition may be well known but if a new use for it is found, unknown until the time the invention is disclosed, the invention will qualify within the meaning of the words “the invention is new”.

The Court of Appeal recognized that finding a new use for a known substance is no less novel and innovative than finding the substance itself. It may even happen that the new use will revolutionize the particular industry or area of knowledge.

Although Swiss-style claims may offer a valid way of framing claims for second and subsequent medical uses of a known substance, a purpose-limited product claim may also suffice.

Swiss-style claims are allowed by IPOS (see The Examination Guidelines for Patent Applications at IPOS dated 14 February 2014).

The Court of Appeal saw no reason to disagree with the validity of such claims, but opined that if Section 14(7) is given the wider and purposive interpretation set forth above, the need for Swiss-style claims in Singapore would probably cease.

If Section 14(7) does cover second and subsequent medical uses of known substances, then a purpose-limited product claim may be sufficient to obtain a patent and Swiss-style claims may not be necessary at all. A purpose-limited product claim could take the following form: “Compound X for use in the treatment of disease Y.”

Commentary:

The Court of Appeal adopted a strict approach in the present case and opined that where the patent in question is obviously invalid, such that the threshold criteria for patentability is not met, such obvious invalidity would be fatal to any amendment application to cure invalidity.

Nonetheless, as fairly pointed out by the Court of Appeal itself, such an approach would affect only a small number of patents since any patent application containing claims similar to the granted claims, i.e. method of treatment claims, which is made under the present “positive-grant” system would either be rejected or be amended into an acceptable form before grant.

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